Handover Procedures in a Wireless Communications System

1. A wireless terminal, comprising: a memory module; and at least one processor coupled to the memory module, the at least one processor being configured: to exchange messages with a serving node to support a handover to a target node in a radio access network, each of the exchanged messages being assigned an identifier comprising sequence numbers, and sequence numbers assigned to uplink messages being independent of sequence numbers assigned to downlink messages; to determine whether the wireless terminal has received a stale message when a first handover command message is not received from a serving node, the stale message comprising a second handover command message from the target node transmitted after the handover based on the identifier, and to abort a portion of a reconfiguration following an error in the handover when the first handover command message is received from the serving node, the error being based on reconfiguration information received in a downlink message.

2. The wireless terminal of claim 1 , wherein the processor is further configured to transmit a message to the target node to support the handover of the wireless terminal, wherein the message indicates the highest sequence number for the messages sent to the serving node.

3. The wireless terminal of claim 1 , wherein the processor is further configured to receive a message from the target node to support the handover of the wireless terminal, wherein the message received from the target node indicates the highest sequence number for the messages received from the serving node.

4. The wireless terminal of claim 3 , wherein the processor is further configured to determine that a message received from the target node comprises a sequence number equal to or less than the highest sequence number of the messages received from the serving node is a stale message.

5. The wireless terminal of claim 1 , wherein the processor is further configured to ignore the stale message received from the target node following the handover.

6. A wireless terminal, comprising: means for exchanging messages with a serving node to support a handover to a target node in a radio access network, each of the exchanged messages being assigned an identifier comprising sequence numbers, and sequence numbers assigned to uplink messages being independent of sequence numbers assigned to downlink messages; means for determining whether the wireless terminal has received a stale message when a first handover command message is not received from a serving node, the stale message comprising a second handover command message from the target node transmitted after the handover based on the identifier; and means for aborting a portion of a reconfiguration following an error in the handover when the first handover command message is received from the serving node, the error being based on reconfiguration information received in a downlink message.

7. The wireless terminal of claim 6 , further comprising means for transmitting a message to the target node to support the handover of the wireless terminal, wherein the message indicates the highest sequence number for the messages sent to the serving node.

8. The wireless terminal of claim 6 , further comprising means for receiving a message from the target node to support the handover of the wireless terminal, wherein the message received from the target node indicates the highest sequence number for the messages received from the serving node.

9. The wireless terminal of claim 8 , wherein the means for determining whether the wireless terminal has received the stale message from the target node comprises means for determining that a message received from the target node comprises a sequence number equal to or less than the highest sequence number of the messages received from the serving node is a stale message.

10. The wireless terminal of claim 9 , further comprising means for ignoring the stale message received from the target node following handover.

11. A method of handing over a wireless terminal from a serving node to a target node in a radio access network, comprising: exchanging messages with a serving node to support the handover of the wireless terminal, each of the exchanged messages being assigned an identifier comprising sequence numbers, and sequence numbers assigned to uplink messages being independent of sequence numbers assigned to downlink messages; determining whether the wireless terminal has received a stale message when a first handover command message is not received from a serving node, the stale message comprising a second handover command message from the target node transmitted after the handover based on the identifier; and aborting a portion of a reconfiguration following an error in the handover when the first handover command message is received from the serving node, the error being based on reconfiguration information received in a downlink message.

12. The method of claim 11 , further comprising transmitting a message to the target node to support the handover of the wireless terminal, wherein the message indicates the highest sequence number for the messages sent to the serving node.

13. The method of claim 11 , further comprising receiving a message from the target node to support the handover of the wireless terminal, wherein the message received from the target node indicates the highest sequence number for the messages received from the serving node.

14. The method of claim 13 , wherein determining whether the wireless terminal has received the stale message from the target node comprises determining that a message received from the target node comprises a sequence number equal to or less than the highest sequence number of the messages received from the serving node is a stale message.

15. The method of claim 14 , further comprising ignoring the stale message received from the target node following handover.

16. A non-transitory computer-readable medium for use in a wireless terminal to handover the wireless terminal from a serving node to a target node in a radio access network, the non-transitory computer-readable medium including instructions stored thereon, the instructions comprising: program code to exchange messages with a serving node to support the handover of the wireless terminal, each of the exchanged messages being assigned an identifier comprising sequence numbers, and sequence numbers assigned to uplink messages being independent of sequence numbers assigned to downlink messages; program code to determine whether the wireless terminal has received a stale message when a first handover command message is not received from a serving node, the stale message comprising a second handover command message from the target node transmitted after the handover based on the identifier; and program code to abort a portion of a reconfiguration following an error in the handover when the first handover command message is received from the serving node, the error being based on reconfiguration information received in a downlink message.

17. The non-transitory computer-readable medium of claim 16 , wherein the instructions further comprise program code to transmit a message to the target node to support the handover of the wireless terminal, wherein the message indicates the highest sequence number for the messages sent to the serving node.

18. The non-transitory computer-readable medium of claim 16 , wherein the instructions further comprise program code to receive a message from the target node to support the handover of the wireless terminal, wherein the message received from the target node indicates the highest sequence number for the messages received from the serving node.

19. The non-transitory computer-readable medium of claim 18 , wherein the program code to determine further comprises program code to determine whether a message received from the target node comprises a sequence number equal to or less than the highest sequence number of the messages received from the serving node is a stale message.

20. The non-transitory computer-readable medium of claim 19 , wherein the instructions further comprise program code to ignore the stale message received from the target node following the handover.